42 lines
1.5 KiB
NASM
42 lines
1.5 KiB
NASM
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;clean registers
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;load starting pos and starting pos +1 into memory
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;subtract first value (starting pos) from second value (starting pos +1)
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;if result is negative or zero, write 0 to x4000
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;if positive, loop back and do the same with the next two memory locations
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.ORIG x3000 ;start point
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AND R6, R6, #0 ;clean R6
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AND R5, R5, #0 ;clean R5
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AND R4, R4, #0 ;clean R4
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AND R3, R3, #0 ;clean R3
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LOOP LD R6, FIRSTPOS ;block loads first pos into register increments memory value by one and store back
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ADD R6, R6, #1
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ST R6, FIRSTPOS
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LD R6, SECONDPOS ;block loads second pos into register increments memory value by one and store back
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ADD R6, R6, #1
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ST R6, SECONDPOS
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LDI R3, FIRSTPOS ;load values into memory and then create negative out of it
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LDI R4, SECONDPOS
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ADD R4, R4, #0 ;see if the array ends
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BRz FINISH
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NOT R3, R3
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ADD R3, R3, #1
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ADD R5, R3, R4 ;add R3 and R4 into R5
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BRp LOOP
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LD R6, ZERO
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STI R6, RESULT
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HALT
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FINISH LD R6, ONE
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STI R6, RESULT
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DONE HALT
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FIRSTPOS .fill x4000
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SECONDPOS .fill x4001
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RESULT .fill x4000
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ONE .fill x0001
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ZERO .fill x0000
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.END
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